Shotshell over-powder wad and shot cup



Feb. 13, 1968 G. L.. HERTER SHOTSHELL OVER-POWDER WAD AND SHOT .CUP

Filed April 26, 1966 United States Patent Oice 3,368,489 Patented Feb. 13, 1968 3,368,489 SHOTSHELL OVER-POWDER WAD AND SHOT CUP George L. Herter, Waseca, Minn., assgnor to Herters Inc., Waseca, Minn., a corporation of Minnesota Fiied Apr. 26, 1966, Ser. No. 545,292 Claims. (Cl. 102-95) ABSTRACT 0F THE DISCLGSURE An over-powder wad and shot cup for a shell casing is constructed of compressible and iiexible material such as polyethylene, and is provided with a flat, powderengaging disc connected to the circular base of the shot cup by a compressible, plastic post extending axially of the wad and shot cup structure. A sealing and centering disc is connected to the Apost between the bottom of the shot cup and the iiat powder-engaging disc, and is provided with circular bands of teeth about its outer periphery for sealing against the inner wall of the cartridge case and gun barrel to prevent the leakage of combustion gases. The outer peripheries of the shot cup base and the at powder-engaging disc may also be provided with outwardly projecting teeth.

This invention relates to firearm cartridges and more particularly relates to an over-powder shotshell wad and shot cup for shotshells.

In the construction of shotshells, an over-powder wad is used inside the shotshell casing to position the powder or propellant charge in proper relation to the primer cap and to separate the pellets or shot from the propellant charge. The shot is typically contained in a shot cup positioned above the over-powder wad. The over-powder wad further performs the function of preventing gases generated upon detonation within the propellant charge from entering the portion of the shotshell which contains the shot or pellets. Leakage of the gases into the area of the pellets causes undesirable pressures among the pellets thereby resulting in a poor shot pattern as the shot leaves the shotshell casing. Other functions of the over-powder wad include cushioning the pellets within the shot cup at the time of detonation. Absorbing and cushioning the shock and sealing the gases is extremely important in providing optimum results from a shotshell.

Anobject of my invention is to provide a new and irnproved shotshell of simple and inexpensive construction and operation.

Another object of my invention is the provision of an over-powder shotshell wad which may be re-used.

Still another object of my invention is the provision of an over-powder wad which seals gases generated upon detonation from escaping into the shot containing portion of the shotshell.

A further object of my invention is the provision of a shotshell over-powder wad which absorbs the shock and cushions the pellets, at the time of detonation, from any undesirable pressures.

A still further object of my invention is the provision of a combination over-power wad and shot cup which may be reused and which properly seals the gases and cushions the pellets without cracking or distorting.

These and other objects and advantages of my invention will morel fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views and in which:

FIG. l is a vertical sectional view taken along an axial plane of a shotshell.

FIG. 2 is a perspective view of my over-powder wad and shotshell cup structure.

' FIG. 3 is an enlarged view taken along the section lines 3-3 of FIG. 1.

FIG. 4 is a partial vertical sectional view of a shotshell showing my over-powder wad and shot cup at the precise point of detonation.

FIG. 5 is a partial elevation view of an alternate form of my over-powder Wad and shot cup with portions broken away for clarity.

FIG. 6 is a partial elevation view of another alternate form of my over-powder wad and shot cup with portions broken away for clarity.

FIG. 7 is a partial elevation view of still another alten nate form of my invention.

FIG. 8 is an enlarged view taken along the lines 8 8 of FIG. 7.

Referring to the drawings for a more detaiied description of my invention, a complete shotshell is shown in FG. l, indicated by the numeral 10. The shotshell 10 comprises, typically, a suitable metal base 11, typically constructed of brass. The base or head 11 surrounds a generally tubular casing 12 which may be constructed of metal, paper, plastic or the like. A primer cap is shown at 13 seated within the brass head 11. The primer cap is inserted within the propellant chamber 14 which contains a propellant charge 15. The over-powder wad and shot cup is disposed within casing 12 above the charge 15, indicated, in general, by numeral 16. Pellets or shot are indicated at 17 and are contained within shot cup 17a. Shot cup 17a is integral with the over-powder wad indicated, in general, by the numeral 18. The shot 17 is held within the shot cup 17a by a sealing wad 19 which is crimped or held in place by the inturned outer end 19a of the shotshell casing 12.

As shown in FIG. l, the over-powder wad and shot cup structure 16 includes a shot cup portion 17a and a wad portion 18 connected by a post 20. Wad and shot cup 16 is generally of integral molded construction and typically formed of compressible, deformable, flexible and yieldable plastic material such as polyethylene. The wad and shot cup is generally of cylindrical configuration with the diameter of the wad portion 18 being substantially the same as' the cup portion 17a. Cup portion 17a includes a base portion 21 from which post 20 extends axially downwardly to wad 13. Wad 18 includes a powder engaging disc 22 of substantially the same diameter as cup portion 17a and having a substantially iiat powder engaging surface 23. Disc 22 includes downwardly projecting teeth 24 having a generally saw tooth cross-sectional configuration adapted to sealin-gly engage the inner Walls of casing 12. The teeth are concentric and spaced apart. Helical teeth may also be turned on the desired surfaces with the teeth directed in a predetermined direction. A substantially iiat disc 25 is interposed substantially midway between base 21 and powder engaging base 22, and is joined to base 22 by axial post 26. Disc 25 is of substantially the same diameter as the diameter of cup portion 17a and includes downwardly projecting teeth 27 similar to teeth 24. Teeth 27 are adapted to sealingly engage the inner wall of casing 12. Posts 20 and 26 are generally cross-shaped in cross-section, are disposed axially and normal to disc 25. The connecting posts may vary in conguration and in hardness of plastic to arrive at optimum operating characteristics. FIG. 3 clearly indicates the cross-sectional configuration of posts 20 and 26.

Referring to FIG. 2, the combination shotshell overpowder wad and shot cup is shown in perspective. The shot cup 17a includes a pair of generaly diametrically opposed slotted openings 28 formed therein. The slotted openings are typically longitudinal and extend substantially the full length of the cylindrical wall portion of the shot cup 17a but terminate just short of the outer end thereof so that they are not in communication with the continuous annular marginal edge of the cup wall 29 and the cup 17a will therefore not tend to materially distort or flare out upon leaving the shotshell casing after firing.

FIG. 4, taken at the precise time of detonation, shows the deformation of the wad and cup which is momentariy caused by the explosion. The deformation takes place without cracking or distorting the wad or shot cup and also affords greater sealing between the wad 18 and casing 12 due to plastic flow which compresses the wad thereby increasing the disc diameters. Teeth 24 and 2'7 are forced in more effective sealing relation against casing 12 and, due to their configuration, ilex thereby sealing without permanently distorting or cracking the wad. As shown in the drawing, base 21 exes upwardly and disc 22. exes downwardly. Posts 2t) and 26 are prevented from collapse by middle disc 25 which substantially retaiiis its shape. Plastic ow takes place as shown with a widening of the posts at the point of engagement with disc 25. This provides a cushioning effect which absorbs the pressure created upon detonation. Further, the pellets 17 are protected from adverse pressures which would prevail except for the cushioning and sealing of the wad 18. Middle disc 25 maintains the over-powder wad and shot cup in alignment within the casing 12 and further prevents collapse or undue axial misalignment of posts 20 and 26. Disc 25 also prevents flexing of discs 22 or 25 past a predetermined limit.

Since the shot cup and over-powder wad of my invention is typicaly used by one who wishes to reuse the corn- `bonents when reloading shells, it is most important that the pressures generated at detonation be absorbed by the shot cup and wad without distortion or cracking of the unit. Referring to FIG. 1, the powder engaging surface 23, contacts powder 15 with teeth 24 and 27 securely engaging the inner surface of casing 12. Shot 17 is placed in shot cup 17a and the casing 12 is crimped about shot retaining disc 19 by the crimped end 19a. This with the addition of a primer 13, completes a shotshell. FIG. 4 and the above description relating thereto, `discloses that which happens within a shotshell at the time of detonation. Since the base 21 and powder engaging disc 22 ex as indicated in drawing of FIG. 4, the shock and pressures of detonation are absorbed thereby preventing harm to the wad or shot cup yet maintaining maximum sealing and cushioning features.

Reference is now made to FIG. 5, showing an alternate over-powder wad and shot cup. This alternate embodiment of my invention includes a shot cup 17a" having a base 21 with outwardly projecting teeth 31 disposed thereon and adapted to engage a shotshell casing. The teeth 31 are concentric and spaced a predetermined distance apart. A post joins base 21 to a middle disc 25 having teeth 32 disposed thereon and projecting outwardly therefrom. Post 26 conne-cts middle disc 25 to powder engaging disc 22 which includes teeth 33 projecting outwardly therefrom and adapted to engage the inner wall of a shotshell casing. Teeth 33 are concentric and spaced apart a predetermined distance. Teeth 31, 32 and 33, respectively, have substantially the same diameter and are adapted to sealingly engage a shotshell casing to Aprevent gases generating at detonation from flowing upwardly past the sealing teeth. Further, the teeth are adapted to flex. and absorb the shock at detonation to prevent distortion and cracking of the over-powder wad and shot cup.

Still another alternate form of my invention i`s shown in FIG. 6 and includes a base wad 21" attached to shot cup 17a. Base 21" includes upwardly projecting teeth 34 which are concentric and spaced apart a predetermined distance. Teeth 34 have 4a saw tooth cross-sectional configuration and a diameter suflicient to engage the inner Walls of a shotshell casing in sealing relation thereto. Post 20 joins disc 21 to a middle sealing disc 25," which includes upwardly projecting teeth 35 which are spaced apart a predetermined distance and are concentric. Post 26 joins middle disc 25 to powder engaging disc 22" which includes teeth 36 disposed thereon and projecting upwardly. Teeth 34, 35 and 36 are of substantially the same diameter and are adapted to ex at detonation thereby preventing distortion or cracking of the wad or shot cup at the time of detonation. This allows the operator to re-use the shot cup and wad.

Referring to FIG. 7, a still further embodiment of my invention is shown and includes a post 37 joining base 21" of shot cup 17a to a middle disc 25". Disc 25 has downwardly projecting teeth 38 disposed thereon. Teeth 38 have a saw tooth cross-sectional configuration, are concentrically spaced and have a diameter such that the teeth are adapted to engage the inner walls of a shotshell casing in sealing relation thereto. Post 39 joins disc 25 to powder engaging base 4t) which has a flat powder engaging surface 41. Discs 21 and 4t) are adapted to tlex at the point of deto-nation providing a cushioning effect to absorb the shock of detonation without distorting or cracking the shot cup or the over-powder base wad thus permitting reuse ofthe unit.

In the above mentioned embodiment, posts 37 and 39 have a circular cross-sectional configuration as indicated in FIG. 8. The diameter of post 37 or 39 is determined based upon design requirements and may be varied from one unit to another dependent upon the results desired by the operator.

It will, of course, be understood that various changes may be made in the form, detaiis, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

1. Ari over-powder wad and shot cup structure adapted for use within a shotshell casing, comprising:

a generally tubular, resilient shot cup having an open outer end and a closed inner end adapted to contain the shot of said shotshell, said shot cup including a deformable inner end base portion having an annular outer surface adapted to engage said shotshell casing;

a resilient, powder-engaging member coaxial with said shot cup and axially spaced a predetermined distance from said inner end base portion of said shot Cup, said powder-engaging member having an annular outer surface adapted to engage said shotshell casing, and said powder-engaging member being adapted to overlie the propellent charge of said shotshell;

compressible and deformable axial post means connecting said inner end base portion of said shot cup with said powder-engaging member; and v a disc of deformable, plastic material integral with said axial post means for radial expansion therewith, said disc being disposed intermediate said shot cup inner end base portion and said powder-engaging member and having an annular outer periphery with'readily deformable means thereon to seal against said shotshell casing under inuence of radial expansion of said disc and the post means as said post means is compressed axially by the expanding gases of the ignited explosive charge of said shotshell.

2. The structure recited in claim 1 wherein:

said readily deformable means on said disc periphery includes teeth means adapted to sealingly engage said shotshell casing in pressure absorbing relation therewith as said annular outer periphery of said intermediate disc moves radially outwardly.

3. The structure of claim 2 wherein: said teeth means comprises a plurality of axially spaced,

circumferentially extending elements having a sawtooth cross-sectional configuration.

4. The structure of Claim 1 wherein:

said powder-engaging member comprises a tiexible,

Circular disc of predetermined thickness having a sub- 5 6 stantially flat, powder-engaging surface adapted to References Cited confront the propellent charge of said shotshell, the UNITED STATES PATENTS Outer periphery of said flexible, powder-engaging disc having readily deformable means to seal against the 3279375 10/1966 Hrter 10242 3,299,813 1/1967 Rickey 102-42 shotshell casing. Y n 5 3 2 5, The structure of claim 4, and further including: 309994 3/1967 Lage 102-4 a plurality of circumferential sealing and pressure abl l sorbing teeth elements formed in said annular outer BENJAMIN A' BORCHELT Primary Examine" surface of said shot cup base portion. ROBERT F. STAHL, Exalmner. 

